There is known one shown in FIG. 9 and FIG. 10, as a conventional electromagnetic operating device which operates a power switchgear by electromagnetic force to perform opening and closing operation, the power switchgear being equipped with, for example, a vacuum circuit breaker. FIG. 9 is a front view; and FIG. 10 is a side view.
In FIG. 9 and FIG. 10, the electromagnetic operating device includes a case 10 formed in a box shape; the case 10 has an opening 12 on the front side; and a front cover (not shown in the drawing) is attachably and detachably fixed on the front side of the case 10. Within the case 10, a capacitor 16 and a control substrate 18 are separately and independently arranged centering on an electromagnet 14, respectively; the electromagnet 14 is fixed at the bottom side center of the case with bolts and nuts; and the capacitor 16 and the control substrate 18 are separately fixed to facing lateral faces of the case, respectively. More specifically, the capacitor 16 is fixed to the left lateral face of the case 10 with bolts and nuts; and the control substrate 18 is fixed to the right lateral face of the case 10 via spacers 20 with bolts and nuts.
The case 10 incorporates a secondary plug 22 and cables 24, 26, 28, and 30 and also incorporates an auxiliary contact 34, an indication plate 36, and a counter 38, which serve as a state detection mechanism that detects a state of a vacuum circuit breaker (vacuum interrupter) 32 serving as a switchgear. The cable 26 is connected to the auxiliary contact 34; and the cable 30 is connected to a coil 48 of the electromagnet 14.
The control substrate 18 receives a supply of electric power from a secondary plug 22 and also receives a signal by a closing command or a contact opening command (interrupting command) from a digital relay or an analog relay; and the control substrate 18 is mounted with a control logic unit that performs logical operation for controlling driving of the electromagnet 14, a charging and discharging circuit for charging and discharging the capacitor 16, and a relay and a relay contact for controlling the energization direction of the coil (electromagnet coil) 48, and the like (not shown in the drawing). Further, the control substrate 18 is mounted with a light-emitting diode 50 which shows that charging of the capacitor 16 is completed; and the control substrate 18 is mounted with an push button for “ON” (push button switch) 52 which is for commanding closing to the vacuum interrupter 32 by a manual operation and an push button for “OFF” (push button switch) 54 which is for outputting a contact opening command (interrupting command) to the vacuum interrupter 32 by a manual operation.
The auxiliary contact 34, the indication plate 36, and the counter 38 are arranged on the upper side of the electromagnet 14 and are coupled to a plate 56, respectively, as a state detection mechanism of the vacuum circuit breaker 32, resulting in a configuration integrated with the electromagnet 14. The electromagnet 14 includes a movable core 58, a fixed core 60, the coil 48, a shaft 62, two movable flat plates 64 and 66, a permanent magnet 68, iron covers 70 and 72 formed in a tubular shape, iron support plates 74 and 76, a fixing rod 78, and the like. The coil (electromagnet coil) 48 is incorporated in a coil bobbin 48a disposed between the support plate 74 and the support plate 76. The fixing rod 78 is fixed to the bottom side of the case 10 with bolts and nuts and is also fixed to a base 80.
The shaft 62 is disposed at a central portion of the electromagnet 14 and is also set along a vertical direction. Furthermore, a configuration is made such that the upper side of the shaft 62 is inserted into a through hole 82 of the plate 66 and the lower side thereof is inserted into a through hole 84 of the support plate 76 to be movable up and down and slidable. The movable core 58 and the movable flat plates 64 and 66 are fixed to the outer circumferential surface of the shaft 62 with nuts; and a shaft 88 is coupled to the lower side of the shaft 62 via a pin 86.
Further, a support plate 90 is coupled to the lower side of the shaft 62; and a ring-shaped interrupting spring 92 that draws a circle centered on the axial center of the shaft 62 is mounted between the support plate 90 and the base 80. The interrupting spring 92 applies an elastic force, which is for separating the movable core 58 from the fixed core 60, to the shaft 62 via the support plate 90. Furthermore, the permanent magnet 68 is disposed around the movable core 58 and is fixed to the mounting plate 74. The fixed core 60 is fixed to the mounting plate 76 with bolts.
Furthermore, the lower side of the shaft 88 is coupled to a pair of levers 96 via a pin 94. The lever 96 is configured as one element of a linking mechanism that converts the transmission direction of a driving force associated with electromagnetic force generated by the electromagnet 14 and is coupled to a lever 100 via the shaft 98. The lever 100 is coupled to a joining plate 104 via a pin 102.
The joining plate 104 is inserted into an insulation pedestal 110 fixed to the base 80 so as to be capable of moving upward and downward (reciprocating); and a contact pressure spring holding member 112 is formed on the upper side of the joining plate 104. The contact pressure spring holding member 112 is formed with a through hole; and an axial end portion of an insulation rod 114 is inserted into the through hole. A contact pressure spring 120 is mounted between the contact pressure spring holding member 112 and the bottom side of the insulation rod 14.
The upper side of the insulation rod 114 is coupled to a movable feeder 122 via a flexible conductor 121 and is coupled to a movable conductor 124 of the vacuum interrupter 32. The movable conductor 124 is coupled to a movable contact (not shown in the drawing) and a fixed contact (not shown in the drawing) is disposed facing the movable contact. The fixed contact is coupled to a fixed conductor 126 and is incorporated in an insulation cylinder 128 together with the movable contact.
In this case, when the closing command is input to the control substrate 18, the coil (electromagnet coil) 48 of the electromagnet 14 is energized by the signal from the control substrate 18; a magnetic field is formed around the coil 48 by a path connecting the movable core 58, the fixed core 60→the mounting plate 76→the cover 72→the mounting plate 74→and the movable core 58; a downward suction force is exerted on the bottom side end face of the movable core 58; the movable core 58 moves to the fixed core 60 side; and the movable core 58 is suctioned to the fixed core 60. At this time, the direction of the magnetic field formed by the permanent magnet 68 is also the same as the direction of the magnetic field generated associated with excitation of the coil 48; and therefore, the movable core 58 moves to the fixed core 60 side in a state where the suction force is enhanced.
When a closing operation (suction operation) by the electromagnet 14 is performed, the shaft 62 moves downward against the elastic force of the interrupting spring 92 and the driving force associated with the electromagnetic force generated by the electromagnet 14 is transmitted to the lever 96. The driving force is transmitted to the joining plate 104 via the shaft 98 and the lever 100; the movable conductor 124 moves upward; the movable contact comes into contact with the fixed contact; and a closing operation of the vacuum interrupter 32 is performed. In the closing operation of the vacuum circuit breaker 32, the contact pressure spring 120 is not compressed until the movable contact comes into contact with the fixed contact; however, when the movable contact comes into contact with the fixed contact, the contact pressure spring 120 is compressed; and after that, the contact pressure spring 120 continues to be compressed until the closing operation is completed. On the other hand, the interrupting spring 92 continues to be consistently compressed during the closing operation of the vacuum interrupter 32.
Next, when the contact opening command (interrupting command) is input to the control substrate 18 and the signal associated with the contact opening command is output from the control plate 18 to the coil 48, a current in a direction opposite to that at the time of closing flows through the coil 48 and a magnetic field in a direction opposite to that at the time of closing operation is formed around the coil 48. In this case, magnetic flux generated by the coil 48 and magnetic flux generated by the permanent magnet 68 are cancelled out with each other and a suction force at the axial end face (lower face) of the movable core 58 is weaker than an elastic force generated by the interrupting spring 92 and the contact pressure spring 120; and therefore, the movable core 58 is separated from the fixed core 60 to move in the upward direction.
When the shaft 62 moves upward associated with the movement of the movable core 58, the joining plate 104 moves downward in conjunction with the upward movement of the lever 96, the movable contact of the vacuum interrupter 32 is separated from the fixed contact, the contact between the fixed contact and the movable contact is released, and a contact opening operation (interrupting operation) of the vacuum interrupter 32 is performed. In this case, when the retention of a closing state of the electromagnet 14 is released, first, the compressed contact pressure spring 120 extends. Then, when the contact pressure spring holding member 112 comes into contact with a washer 116, the contact between the fixed contact and the movable contact of the vacuum interrupter 32 is released, and the interrupting operation of the vacuum circuit breaker 32 and interrupting (opening) operation of the electromagnet 14 are performed simultaneously.
In the process in which the closing operation or the contact opening operation (interrupting operation) by the vacuum interrupter 32 is performed, a closing or interrupting state of the vacuum interrupter 32 is detected by the auxiliary contact 34, the indication plate 36, and the counter 38.
The auxiliary contact 34 is structured such that a normally open contact is ON (closed) when a shaft 142 rotates in one direction and a normally close contact is OFF (opened) when the shaft 142 rotates in a reverse direction. In this case, a lever 138 is formed with a long hole and a pin 136 is inserted into the long hole; and thus, the shaft 142 can be rotated in accordance with the upward and downward movement of the a shaft 62 and ON/OFF of the normally open contact and the normally close contact can be performed in accordance with the rotational operation of the shaft 142.
The indication plate 36 is integrally formed with the leading end side of the lever 140. Then, a letter of “OFF” is marked on the upper side of the front side of the indication plate 36 and a letter of “ON” is marked on the lower side thereof. The letter of “OFF” is visible from the front side of the case 10 when the indication plate 36 is located at a position shown in FIG. 10; and the letter of “ON” is visible from the front side of the case 10 when the indication plate 36 moves upward from the position shown in FIG. 10. More specifically, the configuration is made such that the letter of “OFF” or “ON” is seen from the front side of the case 10 in accordance with the upward and downward movement of the shaft 62.
Furthermore, a spring 148 is disposed on the indication plate 36; one end side of the spring 148 is coupled to an axial end portion of the lever 140 and the other end side is coupled to the counter lever 150 of the counter 38. The spring 148 expands and contracts in response to the rotation of the lever 140; the counter lever 150 rotates centering on a pin 152 and the number of opening and closing operation times of the vacuum interrupter 32 is mechanically counted each time the counter lever 150 rotates.